XP

XP (Extreme Performance) general term in computers indicating greatest performance Microsoft XP, newest graphical operating system of Microsoft (alternative to Windows 95, Windows 98, Windows NT, Windows 2000) XP (xeroderma pigmentosum) (Medicine) genetic disease of dry skin that becomes discolored and is characterized by unusual sensitivity to sunlight XP (XRISTOS) Constantinian symbol, first 2 letters of the Greek word "christos" or "XRISTOS" (meaning "Christ") first used and introduced as a Christian symbol by Constantine I